1. Field of the Invention
The present invention relates to a communications system for transmission, by way of connecting wires and/or a wireless medium, voice, music, text, images and data with a conventional telecommunications network for analog transmission and also segmented digital transmission with local exchanges and transit exchanges, comprising an additional network, superposed on the analog network, for pure digital transmission with its own transit exchanges (long distance network), and comprising digital local exchanges which are connected directly to digital subscriber stations, manifesting analog/digital converters and digital/analog converters, on the one hand, and which are connected, for every transmission connection to be established beyond the local area, either directly to the digital long distance network or to the analog network by way of the analog/digital converters and the digital/analog converters or, in the case of connection to a segmented digital transmission network, by way of a code converter, on the other hand, and comprising digital subscriber stations which constantly, or intermittently, utilize a portion of the bit current, available for voice transmission, for data transmission and/or signaling purposes.
2. Description of the Prior Art
A communications transmission system of this type is described, for example, in an application for United States Letters Patent, Ser. No. 915,051, filed June 12, 1978, which renders possible, in addition to voice transmission, also business teleprinting, telecopying, telephone-individual image transmission, or electronic letter transmission by way of digital subscriber stations. It is possible that constantly, or intermittently, a portion of the bit current available for voice transmission is utilized for data transmission and/or signaling purposes.